The Schiphol CTR is class C, so SVFR is probvably not necessary.
True. Unless the weather falls below VFR minima, in which case you need (and can get) an SVFR clearance through it.
But if the weather is that bad, may I kindly suggest you don't try and cross unless you really know your way around there? ATC will send you all over the place if they have to (for separation - they may be using four runways simultaneously while you cross and need to guarantee separation everywhere) and will do so by feeding you all sorts of obscure and sometimes unpronounciable placenames (for a foreigner, that is).
but at least you don't have to stay quite as low.
Schiphol TMA starting at 1500 feet above a former floodplane lying mostly below sea level. London TMA starting at 2500 feet above terrain that rises to 900 feet in places. What's the practical difference?